April weather forecastO'Fallon, MO
April
Weather in April
April embodies Spring fully, with a bloom in temperature noticeable from 37.9°F (3.3°C) to a welcoming 47.3°F (8.5°C). The climate becomes milder and the strength of the sun's rays, as indicated by the UV index, further escalates. With an increase in daylight hours and sunshine, and a decrease in rainfall, locals can enjoy outdoor activities. However, humidity persists at a steady 75% keeping things balmy, indicating the arrival of refreshing April showers. The pressure also sees a subtle dip from 30.07" (764mm) to nearly 29.93" (760mm).Temperature
The start of April brings a shift in the average high-temperature, increasing from March's cool 54.1°F (12.3°C) to an enjoyable 65.3°F (18.5°C). During April, O'Fallon's temperature averages to a chilly 47.3°F (8.5°C) at night.Humidity
In O'Fallon, the average relative humidity in April is 75%.Rainfall
In O'Fallon, during April, the rain falls for 13.3 days and regularly aggregates up to 2.48" (63mm) of precipitation. Throughout the year, there are 132.3 rainfall days, and 21.06" (535mm) of precipitation is accumulated.Snowfall
In O'Fallon, snow does not fall in April through October.Daylight
The average length of the day in April is 13h and 14min.On the first day of the month, sunrise is at 6:46 am and sunset at 7:26 pm. On the last day of April, in O'Fallon, sunrise is at 6:05 am and sunset at 7:54 pm CDT.
Sunshine
In O'Fallon, the average sunshine in April is 8.7h.UV index
The average daily maximum UV index in April is 5. A UV Index reading of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for average individuals.Note: A maximum UV index of 5 in April translates into the following recommendations:
Take precautions - Protection against sun damage is advised. To prevent harmful UV exposure, minimize direct contact with the Sun around midday. Experience reduced UV exposure by about half when donning a wide-brim hat. Be mindful! The reflection from snow can increase the Sun's UV radiation nearly twice.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in April
O'Fallon, MO
- Average high temperature in April: 65.3°F
The warmest month (with the highest average high temperature) is July (87.1°F).
The month with the lowest average high temperature is January (37.4°F).
- Average low temperature in April: 47.3°F
The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (23.7°F).
Average pressure in April
O'Fallon, MO
- Average pressure in April: 29.93"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in April
O'Fallon, MO
- Average wind speed in April: 8.9mph
The windiest month (with the highest average wind speed) is January (9.1mph).
The calmest month (with the lowest average wind speed) is July (5.5mph).
Average humidity in April
O'Fallon, MO
- Average humidity in April: 75%
The month with the highest relative humidity is May (79%).
The month with the lowest relative humidity is October (70%).
Average rainfall in April
O'Fallon, MO
- Average rainfall in April: 2.48"
The wettest month (with the highest rainfall) is May (2.76").
The driest month (with the least rainfall) is December (0.91").
Average rainfall days in April
O'Fallon, MO
- Average rainfall days in April: 13.3 days
The month with the highest number of rainy days is May (15.7 days).
The month with the least rainy days is February (6.8 days).
Average snowfall in April
O'Fallon, MO
- Average snowfall in April: 0"
The month with the highest snowfall is February (1.61").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in April
O'Fallon, MO
- Average snowfall days in April: 0.3 days
The months with the highest number of snowfall days are January and February (5.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in April /
Average sunshine in April
O'Fallon, MO
- Average daylight in April: 13h and 12min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in April: 8h and 42min
The month with the most sunshine is June (Average sunshine: 10h and 30min).
The months with the least sunshine are January and February (Average sunshine: 4h and 42min).
Average sunshine days in April
O'Fallon, MO
- Average sunshine days in April: 14.9 days
The month with the most sunshine days is December (20.6 days).
The month with the least sunshine days is July (12.6 days).
Average UV index in April
O'Fallon, MO
- Average UV index in April: 5
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in April
O'Fallon, MO
- Average cloud cover in April: 41
The month with the most cloud cover is January (Cloud cover 50).
The months with the least cloud cover are June, July, August and September (Cloud cover 28).
Average visibility in April
O'Fallon, MO
- Average visibility in April: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
